The concept known from the market as “half-engine operation” is used in internal combustion engines having intake manifold injection. In this concept, the injection of fuel into certain cylinders in an internal combustion engine is interrupted in certain operating states for the purpose of reducing the fuel consumption. For example, in an eight-cylinder engine, half of the cylinders are shut off in this way. In order to prevent torque fluctuations or even torque jumps from occurring when the fuel injection into (and thus the combustion in) a subset of combustion chambers is interrupted and when injection is resumed, the air charge in the combustion chambers is increased prior to an interruption and the ignition angle is retarded in such a way that the torque remains the same overall.
If a subset of combustion chambers is shut off by interrupting the injection, the ignition angle is suddenly advanced at the time of shut-off. In this way, the combustion chambers into which fuel continues to be injected are able to immediately compensate for the dropping power of the shut off combustion chambers. This would not be possible by simply increasing the air filling at the time of shut-off due to the inertia of the filling path. The operation is reversed when injection into the subset of combustion chambers in question is resumed after a previous interruption.
Furthermore, the principle of overrun shut-off is also known in which not only a subset of the combustion chambers but all combustion chambers are temporarily shut off in the overrun mode.
An object of the present invention is to provide a method mentioned at the outset in which the operating range of the internal combustion engine in which the fuel supply to at least one subset of the combustion chambers may be temporarily interrupted is extended with low emissions at the same time.